Continuously driven thread transporting means



Jun; 13, 1967 R. SCHMIDT ETAL v coNwmuous'm DRIVEN THREAD TRANSPORTING MEANS 'Filed March 22, 1966.

5 Sheets-Sheet 1 FIG.

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r I m M hf Mi 2 h m/ June13,' 1967 R. SCHMIDT ETAL 3,324,685

CONTINUOUSLY DRIVEN THREAD TRANSPORTING MEANS Filed March 22, 1966 5 sneexs she x s June 13,1967 R. SCHMIDT ETAL I 3,32

CONTINUOUSLY DRIVEN THREAD TRANSPORTING MEANS Filed March 22, 1966 S SheeLS-Sheet 4 FIG; 4

June 13, 1967 R. SCHMIDT ETAL 3,324,685

' .CONfIINUOUSLY DRIVEN THREAD TRANSPORTING MEANS Filed March 22, 1966 I v 5 Sheets-Sheet 5 FIG. 5

FIG. 5

United States Patent 21 Claims. cl. 66-132) The present application is a continuation-impart application of our copending application Ser. No. 395,788, filed Sept. 1-1, 1964, now abandoned.

The present invention relates to a continuously driven thread transporting apparatus, and more particularly to a circular knitting machine provided at each knitting station with thread transporting means driven by electric motors in synchronism with the knitting operations performed by the knitting machine.

It is known to provide circular knitting machines with program controlled thread transporting means .at the knitting stations which permit variations of the speed at which the thread is delivered to the knitting needles at the knitting stations. For example, the German Auslegeschrift 1,074,810, the German Patent 907,927, and the British Patent 430,744 disclose such apparatus.

It is also known to transport thread to the knitting stations without any slippage in a positive manner which has the advantage that the loops are of uniform and regular shape which is particularly advantageous for plain and ribbed fabrics.

The thread may be wound in several loops about a transporting roller, or be clamped between a pair of transporting rollers to assure a positive transport without slippage. Other thread transporting apparatus includes a pair of meshing gears between which the transported thread is located.

Positive thread transporting means of this type are located at each knitting station and are driven by means of belts and pulleys, or other transmissions from the needle cylinder, or from a part moving in synchronism with the needle cylinder.

Thread transporting means which have to transport a thread without slippage cannot be provided with independent electric motors since the speed of the transported thread must be proportionate to'the speed of the knitting operation, as represented by the rotary speed of the needle cylinder. Independent drive motors can be used for thread transporting means which operate with slippage in a non-positive manner, but such thread transporting means are suitable only for a patterned fabric in which for different stitches more or less thread is required.

Positive thread transporting means according to the prior art are driven by mechanical transmissions from the needle cylinder of the knitting machine which. has the disadvantage that a great amount of space is required for the transmission parts at each knitting station, which is particularly disadvantageous for modern circular knitting machines with many knitting stations.

It has not been considered possible to provide independent electric motors at each knitting station for driving the thread transporting apparatus, since it is absolutely necessary to drive the thread transporting apparatus at a speed proportionate to the speed of the knitting cylinder. Therefore, the constructions disclosed in the German Patent 1,147,705, the French Patents 916,418 and 870,967, and the US. Patents-2,227,355, 2,160,495 and 2,135,756 which provide electric motors for driving thread transporting apparatus permitting slippage of the thread, are not applicable to thread transporting apparatus which must transport the thread positively and without slippage.

It is one object of the present invention to overcome the disadvantages of mechanically driven positive thread transporting apparatus, and to provide an independent electric drive motor at each knitting station for driving a thread transporting means at a speed proportionate to the variable speed of the knitting machine, and more particularly of the needle cylinder.

Another object of the invention is to provide a polyphase motor operating in synchronism with the knitting machine for driving thread transporting apparatus.

Another object of the invention is to control the rotary speed of the motor by supplying to the same a voltage whose frequency is controlled by a movable part of the knitting machine, such as the needle cylinder.

A related object is to generate an alternating voltage by impulses produced in synchronism with the rotation of the needle cylinder of a cricular knitting machine.

Another object of the invention is to control a synchronous motor by the voltage of a polyphase generator driven by the knitting machine.

With these objects in view, one embodiment of the invention relates to a knitting machine which has a thread transporting apparatus, preferably at each knitting station; generator means controlled by the knitting machine to generate impulses preferably timed to produce a polyphase alternating voltage 'Wh'OSC frequency is proportionate to the operational speed of the knitting machine; a motor, for example a synchronous motor, receiving the voltage from the generator; and thread transporting means at each knitting station connected to and driven by a motor at the same station. The polyphase alternating voltage produces a rotary field in a synchronous motor so that the same is driven at a rotary speed proportionate to the frequency of the voltage and to the operational speed of the knitting machine. Consequently, the motor drives the thread transporting meanscontinuously at a varying speed proportionate to any varied speed of the knitting machine.

In one embodiment of the invention, portions spaced about the periphery of the needle cylinder are sensed by electromagnetic sensing means producing impulses which are supplied to a transducing generator capable of trans forming uniformly spaced impulses into a polyphase voltage. Such voltage is supplied to the synchronous motor driving the thread transporting means.

In another embodiment of the invention, a rotary disc having three circuluar rows of staggered perforations and rotated from the needle cylinder is illuminated so that staggered light impulses are produced which are received by three photoelectric sensing means producing impulses forming a three phase alternating voltage for driving the synchronous motors of the thread transporting means. In this embodiment, the photoelectric sensing means function as generators of the polyphase alternating voltage.

In another embodiment of the invention, a polyphase generator is mechanically driven by the needle cylinder, either directly or through a transmission, and supplies a polyphase voltage to the synchronous motors by which the thread transporting means are driven.

By driving the positively operating slippage-free thread transporting means at a speed directly proportionate to the number of revolutions of the knitting cylinder, the ratio between the number of revolutions of the needle cylinder and the speed of the positively transported thread being formed. Information regarding the type of bed portion of a knitted fabric without pattern, the speed of the transported thread must be varied to supply the amount of thread required for the particuluar stitches. The ratio between the number of revolutions of the needle cylinder and the speed of a transporting means must be changed for such different stitches, but nevertheless the speed of the transporting means must vary proportionate with variations of the number of revolutions of the needle cylinder while maintaining the ratio for the respective stitch.

In known positively-transporting program controlled thread transporting apparatus, each thread transporting means must have a mechanical device for varying the thread transporting speed in accordance with the amount of thread required for a particular stitch.

In accordance with the present invention, a variable transmission is preferably provided between the needle cylinder and the means by which the polyphase voltage is generated. For example, a variable transmission may be provided for driving the perforated disc which produces the light impulses in the second embodiment of the invention. A variable transmission may also be provided between the rotary generator and theneedle cylinder in the embodiment'in which the voltage ot the generator is directly supplied to the synchronous motors.

In the preferred embodiments of the invention, the transmission is gradually variable by an adjusting means shifted by program controlled apparatus. For example, the adjusting means may be mechanically or electromagnetically controlled by selector means to which information is supplied from a decoding translator having sensing means for reading out coded information provided in the form of perforations or light-permeable points on a program tape.

In the embodiment of the invention in which no transmission follows the needle cylinder, the transporting roller is provided with a plurality of circumferential grooves of different diameter, and selector apparatus controls a thread guide by which a thread is placed in a selected groove to move at different speeds during rotation of the synchronous motor at the same speed. The selector apparatus is controlled from a decoding translator having sensing means responding to coded information provided on a program tape. It is possible to control individual knitting stations in accordance with program controlled means, or to provide a common program controlled means for all transporting means at all knitting stations.

By adjustment of the transmission, the speed of the motor driving the thread transporting means is varied in accordance with the nature of the stitch to be knitted irrespective of the rotary speed of the needle cylinder. For example, the knitting cylinder may rotate at a constant speed but by varying the transmission ratio, the transporting means will be operated at different speeds and supply different amounts of thread to the'needles of the knitting machines in accordance With the amount of thread required by the respective stitches which are stitches which is to be knitted is contained in coded form on the program tape by which the transmission is controlled. In another embodiment of the invention, a plurality of variable transmissions are driven from the needle cylinder and drive, respectively, a plurality of polyphase generators. By adjusting the transmission ratios of the several transmissions, the generators are caused to rotate at different speeds. The output terminals of the generators are connected to selector switch means which can be operated by selector means to connect any one of the generators to the synchronous motors at the knitting stations, so that in accordance with the selection, the motors and the respective thread transporting means are driven at different speeds. The selection is again carried out by program controlled means and the selector switch is shifted under the control of a program tape carrying coded information in the form of perforations or light-permeable spots. The information on the program tape relates to the nature of the stitches made at any moment during the rotation of the needle cylinder, and to the amount of thread required for each stitch. By choosing the generator which causes rotation of the synchronous motor at a higher or lower speed, the speed of the thread transporting means is varied as required. by the nature of the stitch, but at the same time the basic dependency of the transporting speed on the rotary speed of the needle cylinder and on the operational speed of the knitting machine is maintained, since any selected generator will move faster or slower when the speed of the needle cylinder is higher or lower. The speed of the transporting means will always vary in accordancewith a varied speed of the knitting machine, but the ratio between a transporting speed and the rotary speed of the rotary cylinder is varied by the.

transmission means in accordance with the present invention.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following descriptionv of specific embodiments when read in connection with the accompanying drawings, in which: I

FIG. 1 is a fragmentary schematic, partly perspective view illustrating a first embodiment of the invention;

FIG. 1a is a diagram illustrating the transformation of impulses into a three phase voltage;

FIG. 2 is a fragmentary schematic, partly perspective view, illustrating a second embodiment of the invention with certain parts shown in FIG. 3 omitted for the sake of simplicity;

FIG. 2a is a plan view illustrating a detail of FIG. 2;

FIG. 3 is a fragmentary schematic perspective view illustrating a third embodiment of the invention;

FIG. 4 is a fragmentary, schematic perspective view illustrating a fourth embodiment of the invention with certain parts shown in FIG. 1 and FIG. 3 omitted for the sake of simplicity;

FIG. 5 is a diagram illustrating an electric circuit for generating a polyphase alternating voltage;

FIG. 5a is a fragmentary sectional view illustrating an electromagnetic sensing means; and

FIG. 6\ is a schematic sectional view illustrating a program controlled selector means.

Referring now to the drawings, and more particularly to FIG. 1, a thread 1 is guided over a transporting roller 3 and through thread guide means, not shown, to a thread guide 21 in the region of a knitting station of a circular knitting machine represented by the needle cylinder 15 and cylinder needles 2. The needle cylinder is rotated so that knitting operations are performed by the cylinder needles 2 and by dial needles, not shown, with the transported thread portion 5. In accordance with the nature of the stitch, different amounts of thread will be required even assuming a constant rotary speed of the needle cylinder, and in order to provide the necessary amount of thread, selector means 8 are provided which operate a shaft 7 with a radial arm ending in a thread guide 6 to place the thread in a selected circumferential groove of the transporting roller 3 when shaft '7 and thread guide 6 are placed in a corresponding angular position. Due to the fact that the diameters of the grooves are different, the thread will be moved at different speeds in accordance with the diameter of the grooves, assuming that the synchronous motor 4 which drives the transporting roller 3 rotates at a constant speed.

As shown in FIG. 6 the selector means 8 includes electromagnetic means including standard different stroke solenoids 8a cooperating with arms 7a on shaft 7'to effect an angular displacement of thread guide 6 through such an angle that the thread can be placed in aselected circumferential groove of transporting roller 3. The solenoids 8a of selector means 8 are connected by conductors 10 to a decoding translator 9 which receives information from a read-out device 11 provided with a transducer head or other sensing means 14 by which information represented in coded form on the program tape 12 is read out when. the tape moves past the sensing means 14. Preferably, the coded information is represented by transverse rows of small light permeable spots on tape 12, and a lamp 13 illuminates the tape so that light passes through the light-permeable spots into the sensing means 14, which include photocells. Information regarding the nature of the stitches to be made is recorded on the program tape, and transferred by the decoding translator as control impulses to the solenoids of selector 8 which causes the thread guide 7 to place the thread in the groove of transporting roller 3 by which the thread will be transported at the speed required by the particular stitch. When the sensing means 14 senses different transverse rows of coded recordings, decoding translator 9 produces different control impulses for energizing corresponding solenoids 8a of selector means 8 toturn the arm 6 of thread guide 5 to different angular positions. Device 11 to 14 is preferably of the type disclosed in the copending application, Elsae'sser, Ser. No. 290,977. The number of spots in each read out transverse row of the program tape is electronically stored, and counted in device 9 during the following step of the program tape whereupon a control impulse energizes one of the coil 8a associated with the respective counted number. This arrangement is known and not an object of the invention.

At each knitting station,a transporting roller 3 and a polyphase motor 4, for example a synchronous motor,

are provided. The three-phase alternating voltage is supplied to the several polyphase motors 4 by a polyphase generator, preferably an ironless transducing generator 20. This transducing generator is provided with transistors and capable of transforming rectangular half waves as schematically-indicated at J", into a three-phase volt- .age, as schematically illustrated in the diagram of FIG.

1a. The phases of the voltage in the three conductors R, S, T are diagrammatically shown in the three upper portions of FIG. 1a, and it will be understood that such a three-phase alternating voltage will produce a rotary field in synchronous motor 4 by which the rotor of the synchronous motor, and thereby the transporting roller 3 will be driven at a speed corresponding to the rotary speed of the rotary field, and to the frequency of the three-phase alternting voltage. This frequency depends on the frequency of the trigger impulses J supplied to the trans- .ducing generator 20.

Ironless transducing generators 20 of the type used in this embodiment of the invention are known, and, for example, described in the German publication Elktronik,

1963, No.9, pages 269 to 273, published by Franzis Verlay, Karls Strasse 35, Munich 37, Germany. The synchronous motor 4 has a three-phase stator winding connected with generator 20 and producing a rotary field for rotating the rotor.

An electromagnetic means 16 is provided at a stationary point near the periphery of the needle cylinder 15, and senses during rotation of the needle cylinder projections 17 forming channels 18 for the cylinder needles 2. Since the number of thus sensed portions 17 of the needle cylinder is constant, the number of impulses produced by the electromagnetic means is proportionate to the rotary speed of the needle cylinder, and consequently to the speed of the knitting operations so that the speed is sensed by electromagnetic means'16.

The electromagnetic sensing means 16 is connected to an amplifier and pulse shaper 19 in which the produced impulses J are shaped into a rectangular half wave shape J" in which form they are supplied to the transducing generator 20. The shape of impulses J is influenced by the needles 2 in the slots of the needle cylinder and consequently not rectangular so that pulse shaper 19 is advantageously used. The grooves 18 cannot be made so narrow as to produce rectangular pulses, particularly due to the magnetic stray fields which occur in the region of the edges of the ridges 17.

As shown in FIG. 5a, the electromagnetic sensing means 16 includes a coil 16a and an iron core 16b located opposite ridges 17 and grooves 18 in the needle cylinder. As shown in FIG. 5, coil 16a is connected with .a bridge circuit B which receives oscillations schematically indicated at G from a KI-I generator G which are modulated due to the changes of the magnetic field of sensing means 16 by the ridges 17, and grooves 18 during rotation of the needle cylinder since the field changes influence the equilibrium of the bridge circuit. The modulated voltage J is supplied over a transformer T to an amplifier A, rectifier R, and demodulator DM of pulse shaper 19 and assumes the wave shapes R and DM. The pulses are shaped to the rectangular shape S by the Schmitt trigger S and pass through a diiferentiator D and amplifier AA to assume the shapes D and J. The output of amplifier AA is connected with the transducing generator 20.

The position of the elements shown in FIG. 1 is entirely schematic, and the proportions and positions of the various elements of the embodiment are different in the actual construction. It willbe understood that a plurality of knitting stations, for example 12 or 24 are provided around thecircumference of the needle cylinder, and that a transporting roller 3, synchronous motor 4, a selector means '8, 6, and a thread guide 21 are provided at each knitting station, while the program controlled decoding translator 9 to 14, the electromagnetic sensing means 16, the pulse shaper 19, and the transducing generator 20 are preferably provided at a single central station. During operation of the knitting machine, needle cylinder 15 rotates, and every portion 17 thereof will cause the impulse producing sensing means 16 to roduce impulses whose frequency is directly proportionate to the rotary speed of the needle cylinder. The impulses are transformed into a three-phase voltage which is supplied to all synchronous motors 4 at the several knitting stations for driving transporting rollers 3 by which the thread 1, 5 is supplied to the several knitting stations..When the speed of the needle cylinder is increased or reduced, the frequency of the impulses will be increased and reduced correspondingly, and the rotary speed of the synchronous motors 4 will be increased and reduced in the same mannerso that the speed of the transported thread is varied in accordance with the rotary speed of the needle cylinder, assuming that the thread remains in the same groove of the transporting roller.

When in accordance with the program recorded on program tape 12, selector means 8 is influenced to move thread guide 6 to place the thread in another groove of transporting roller 3,, the speed of the thread is m0mentarily varied, even if the speed of the synchronous motor and of the needle cylinder remain constant. Of course, any variation of the speed of the needle cylinder will result in a variation of the speed of the mot-0r and of the transporting roller, so that the speed of the thread will be varied, irrespective in which groove the thread is located.

If an individual adjustment of the speed of the thread is required at several or all knitting stations, the program controlled means by which selector means 8 are op- .erated, may be provided at each knitting station, and difnot shown in a housing 40. A gear, not shown,'meshes with the rack portion, and is turned by a selector apparatus corresponding to selector mean-s 8 describes with reference to FIG. 1 and FIG. 6 under the control of a decoding translator and of a sensing mean-s for sensing a program tape as shown at 10 to 14 in FIG. 1, the decoding translator producing electric impulses to displace the shaft of the gear in housing 40 to different angular positions when the sensing means 13, 14 senses different coded recordings on-the program tape. As shown in FIG. 6, coils 8a are selectively energized to turn a shaft 7 which, in the embodiment of FIG. 3, carries instead of an arm 6, a gear (not shown) meshing with the rack portion of rod 39, corresponding to the rack and pinion drive 39a, 41a in FIG. 4. In this manner, the ratio of the transmission is adjusted in accordance with the coded information on the program tape by adjusting rod 3 9, and the output shaft 37 of the transmission will rotate at a higher or lower selected speed.

A three-phase generator 38 is driven by shaft 37 and produces a three-phase voltage in conductors R, S, T, when excited by direct voltage supplied through conductors 38a. The three-phase voltage is supplied to a polyphase motor 4 at each knitting station which may be excited by direct voltage supplied through conductors 4'. These conductors are omitted in FIG. 1 for the sake of simplicity. A synchronous or other rotary field motor 4 at each knitting station of which only four stations I to IV are schematically shown in FIG. 3 directly drives a transporting roller 22 provided with a single circumferential groove to which the thread is guided by a thread guide 4a.

Assuming that the transmission ratio is not varied by shifting friction roller 35 of the adjusting means, needle cylinder 15 will drive the generator 38 through gears 31, 32 and transmissions 34, 35, 36 so that a rotary field will be produced in synchronous motor 4'whose rotary speed is proportionate to the rotary speed of the needle cylinder so that the rotor of the motor and the transporting .roller 22 is driven at a speed proportionate to the rotary speed of the needle cylinder whereby the thread 5 is supplied to the knitting needles at a speed proportional to the speed of the knitting operations, irrespective of whether the needle cylinder rotates faster or slower, since the speed of the transporting roller 22 will be increased and reduced correspondingly. i

For certain stitches, however, a different speed is required, and the speed of the transporting roller is varied for such purpose by adjusting the transmission ratio. This is effected by program controlled means 10 to 13 under control of a program tape 12 as explained with reference to FIG. 1, the program controlled means acting on the selector means 40 by which the adjusting means 39 of the transmission is operated. The speed of the transported thread is changed by the variation of a transmission ratio, since the frequency of the three-phase alternating voltage produced by generator 38 is varied. A single groove in thread guiding roller 22 is sufficient in the embodiment of FIG. 3, since the adaptation to different stitches is accomplished by a variation of transmission ratios.

The embodiment of FIG. 4 is in some respects similar to the embodiment of FIG. 3 inasmuch as a synchronous 7 motor 4 drivinga transporting roller 22, as shown in FIG. 3, is provided at each knitting station. A gear crown on the needle cylinder drives three pinions 32a, 32b, 32c which respectively rotate with friction cones 34a, 34b, 340 connected by adjustable friction rollers 35 with output cones 36a, 36b, 360 secured to the shafts of rotary generators 38a, 38b, 38c. Rods 39a, 3%, 39c of the adjusting means for adjusting the transmission ratio, have rack portions 39a, 39b, 39c meshing with gears 41a, 41b, 410 which can be manually turned by knobs 43a, 43b, 430. By operation of the knobs, the transmission ratios of the three-transmissions are adjusted as required for a particular knitting operation and remain in 8 the adjusted position during the operation. Consequently, the three generators are driven at different selected speeds, and produce three-phase alternating voltages of different frequencies. However, the frequency of each of the voltages will be proportionate to the rotary speed of the knitting cyliner and vary when the rotary speed of a knitting cylinder and the speed of the knitting operations varies. A pair of conductors is connected to all generators for supplying a direct current exciting voltage to the same, while the output terminals R, S, T are connected, respectively, to the three contacts of three selector switches. Terminals R are connected to the contact K1, terminals 8 to the contact K2, and terminals T to the contact K3. Three contact arms H1, H2, H3 cooperate with the three sets of contacts K1, K2, K3 so that by selective shifting of the contact arms, any selected generator can be connected to three conductors 4R, 4S, 4T, which lead to the polyphase motors 4 provided at the several knitting stations, as shown in the upper portion of FIG. 3.

The three contact arms H1, H2, H3 are connected to each other and radially project from a schematically indicated shaft 44 to which they are secured. Shaft 44 is stepwise turned with contact arms H1, H2, H3 by a selector means 45, corresponding to selector means 8 of FIG.- 1 and to selector means 40 of FIG. 3, and operated by program controlled means including a decoding translator 9, and sensing means 14 for sensing coded information on a program tape 12 as described with reference to FIG. 1. Shaft 44 corresponds to shaft 7 of FIG. 6 and is shifted different distances by different energized solenoids 8a so that the contact arms H1, H2, H3 simultaneously engage three contacts in each angular position.

During knitting operations, knitting cylinder 15 rotates at at varying speed, and drives the three generators at different rotary speeds depending on the setting of the transmission ratio by the adjusting means operated by knobs 43a, 43b, 43c.

Assuming that contact arms H1, H2, H3 are in the position illustrated in FIG. 4, generator 380 will be connected to the rotary field motors 4 at the knitting stations and drive the transporting rollers 22 of the same in synchronism with the frequency of the polyphase voltage produced by generator 380. The speed of the transporting rollers will depend on the varying rotary speed of the needle cylinder and on the transmission ratio set by operation of knob 43c and shifting of friction roller 35 between friction cones 36c and 340.

When the program tape 12 carries coded information to which the decoding translator responds to operate selector means 45, the contact arms will be shifted to another position where another generator is effective to produce a three-phase voltage at a different frequency than generator 380. This is due to the fact that the transmission ratio of the respective generator was differently selected.

Consequently, in the other position of the selector switch 44, the respective transporting rollers will be driven by the synchronous motors at a different speed, as required by the nature of the respective switch, although the needle cylinder may move at the same rotary speed. Of course, if the rotary speed of the needle cylinder varies, the speed of the transporting roller 22 is also varied, irrespective of which transmission is effective due to the operation of the selector means.

In the embodiments of FIGS. 3 and 4, special ironless polyphase motors and generators are advantageously used instead of the standard synchronous motors and generators.

Rotary field generators and motors, so called synchro machines are known in which the stator has three windings in Y connection at angles of for a three phase current, while the rotor winding is excited by a single phase current having a constant frequency between 50 and 500 c.p.s. The rotor field induces in the three stator windings of the generator alternating voltages of different amplitude and polarity which depend on the relative 'p'osition of rotor and stator windings and produce in the re ceiving stator windings of the motor a magnetic alternating field of constant amplitude which changes its direction with the rotor of the generator and drives the motor rotor. The advantage of the synchro machines over standard synchronous machines is that they operate at very low rotary speed and that a stator current of low frequency can be used. Motors and generators of this type are, for example, produced by the Standard Electric Lorenz, A. G., of Hellmuth-Hirth Strasse, Stuttgart- Zuffenhausen.

The embodiments of FIGS. 2 and 2a, correspond to the embodiment of FIG. 3, but the synchronous generator 38 is replaced by another type of generator.

As in the embodiment of FIG. 3, a synchronous motor 4 at each knitting station drives a transporting roller 22 having 'a groove receiving the transported thread 5 which passes through a thread guide 30. The needle cylinder, not shown in FIG. 2, has a gear crown 31 meshing with the pinion 32 driving a transmission 34, 35, 36 as described with reference to FIG. 3. The ratio of transmission is adjusted by shifting friction roller 35 by means of a rod 39 having a rack bar portion operated by gear in box 40, as described with reference to FIG. 3, the shifting of the adjusting means 39, 35 being effected under the control of a decoding translator 9 having sensing means 14' for sensing coded information on a program tape 12, as described with reference to FIG. 1.

The output shaft 37 of the tr-anmission drives a circular disc 24, as shown in FIGS. 2 and 2a. The rotary disc 24 has three concentric rows of circumferentially staggered perforations or light-permeable areas 242, 24s, 241, which have wave shapes as best seen in FIG. 2a. Plates 25 and 27 are provided on opposite sides of the rotary disc 24 and have aligned pairs of windows 28a, 28b, 28c, coinciding with the concentric rows of perforations 24!, 24s, 241'. Three lamps 26a, 26b, 26c'are respectively arranged over the upper plate 25 in the region of the windows and illuminate the passing perforations so that three photoelectric sensing means 29a, 29b, 29c located on the other side of disc 24 behind plate 27 are excited whenever a perforation passes a window. Each photoelectric sensing means has two terminal-s, the first terminals of each being connected to each other and to three amplifiers Vr, Vs, Vt and also connected to ground so that they constitute the neutral of this three-phase system. The second terminals of the three photoelectric sensing means are connected to the three amplifiers and through the same to the synchronous motors 4. The amplifiers Vr,

Vs, Vt advantageously include aSchmitt trigger S, a differentiator D, and an amplifier AA, as shown in FIG. 5.

When the knitting machine operates, needle cylinder 15 rotates and drives the rotary disc 24 through the transmission at a speed determined by the tranmission ratio whichmay be changed in accordance with a'knitted pattern as represented on a program tape by shifting adjusting means 3%, 35.

Irrespective of the transmission ratio of the transmis- -sion, the speed'of shaft 37 will depend on the rotary speed of the needle cylinder and vary with the same. The three circular tracks of perforations or light-permeable areas will pass the three lamps 26a, 26b, 26c so that light impulses will pass through the rotating disc 24 and be received by the photoelectric sensing means 29a, 29b, 2%. Due to the fact that the perforations on the disc are wave shaped and staggered in circumferential direction, the electric impulses produced in the photoelectric sensing means, which may be photodiodes, will form a threephase voltage which is amplified by amplifiers V VS, V and conducted to the synchronous motors 4 at the knitting stations. Consequently, the photo diodes act as generator of a polyphase voltage 'by transforming the light impulses into staggered electric impulses.

Evidently, the speed of the synchronous motor will depend on the number of light impulses produced which again depends on the rotary speed of disc 24. This rotary speed can be changed in accordance with the desired stitch by shifting the transmission, but in all conditions of the transmission, variations of the speed of the needle cylinder will result in variations of the speed of the synchronous motors, and consequently of the transported thread.

The thread transporting roller 22 is shown in the em-- bodiments of FIGS. 2 and 3 to be adisc having a narrow peripheral groove in which the thread is tightly guided without slippage. However, it is also possible to provide a cylindrical roller with a smooth surface and to wind the thread about the circumference of the roller to assure a positive transport Without slippage.

It is evident that the shaft of the rotary disc 24 of the embodiment of FIG. 2 could be directly driven from the needle cylinder and correspond, for example, to shaft 33 of FIG. 3. In this event, the adaptation of the I apparatus to specific stitches could be achieved in the manner described with reference to FIG. 1, and the thread is placed in a selected circumferential groove of a transporting roller 3 by a movable thread guide operated by program controlled apparatus.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of apparatus for continuously transporting a thread at a variable speed, differing from the types described above.

While the invention has been illustrated and described as embodied in apparatus for continuously transporting without slippage a thread by transporting rollers driven at a speed proportionate to the speed of the knitting machine, it is not intended to be limited to the details shown since various modifications and structural changes may be made Without departing in any way from the spirit of the present invention. a

Without further analysis, the foregoing will so fully reveal the gist of the present invention, that others can by applying current knowledge readily adapt it for various applications with-out omitting features that from the standpoint of prior art fairly constitute essential characteristics of the specific or generic aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A knitting machine, comprising, in combination, a thread transporting apparatus including generator means controlled by the knitting machine to generate electric impulses at a frequency proportionate to the operational speed of the knitting machine; an electric motor connected to said generator means for receiving said impulses and having a rotor and driven by the same at a speed proportionate to the frequency of said impulses and to said operational speed of the knitting machine; and thread transporting means connected to and driven by said motor whereby said thread transporting means moves at a speed varying proportionate to any varied speed of the knitting machine.

2. A knitting machine according to claim 1 including a movable part for performing knitting operations, and a plurality of knitting stations, and having said thread transporting apparatus at each knitting station; and Wherein said generator means of each thread transporting apparatus is driven by said movable part.

3. A knitting machine according to claim 1 including a rotary needle cylinder and a plurality of knitting starotary speed of said needle cylinder.

4. A knitting machine according to claim 1 wherein l i said thread transporting apparatus includes selector means having a plurality of positions for causing movement of a transported thread at different speeds while said motor rotates at the same speed; and program controlled means for operating said selector means in accordance with the program.

5. A knitting machine according to claim 1 including a rotary needle cylinder; and wherein said generator means include a rotary element having a plurality of perforated portions spaced along a circle and being driven from said needle cylinder to rotate with the same about the center of said circle, a source of light in the region of said perforated portions, and photoelectric sensing means for sensing light passing through said perforated portions so as to produce said electric impulses.

6. A knitting machine according to claim 1 wherein said thread transporting means include a roller driven by said motor and having a plurality of circumferential grooves, each groove being adapted to transport a thread without slippage; and including a thread guide movable between a plurality of positions respectively located aligned with said circumferential grooves for placing a thread into the same; and program controlled selector means for moving said thread guides between said positions whereby the thread moves at dilterent speeds when located in different grooves while said motor moves at the same speed.

7. A knitting machine according to claim 1 including a rotary needle cylinder; a variable transmission driven from said needle cylinder; and adjusting means for varying the ratio of said transmission; and wherein said generator means include a rotary generator connected with said transmission and being driven from said needle cylinder through said transmission.

8. A knitting machine according to claim 7 and including selector means connected with said adjusting means so that in adjusted positions of said transmission the thread is transported at different speeds while said needle cylinder continuously moves at the same speed; and program controlled means for operating said selector means.

9. A knitting machine according to claim 8 wherein 'said program controlled means includes a sensing means for sensing a program tape and a decoding translator receiving impulses from said sensing means and producing control signals for operating said selector means.

10. A knitting machine according to claim 1 including a needle cylinder; a variable transmission driven from said needle cylinder; adjusting means for adjusting the ratio of said variable transmission; and program con trolled means connected to said adjusting means for varying the ratio of said transmission; and wherein said generator means includes a rotary element having perforated portions spaced along a circle and being driven from said needle cylinder to rotate with the same about the center of said circle, a source of light in the region of said perforated portion, and photoelectric sensing means for sensing light passing through said portions and producing said electric impulses when receiving light impulses through said perforated portions.

11. A knitting machine according to claim 1 wherein said generator means produce a polyphase alternating voltage whose frequency is proportionate to the operational speed of said knitting machine; and wherein said motor is a polyphase rotary field motor connected with said generator means to receive said polyphase voltage from the same whereby a rotary field is produced in said motor for driving said motor at a rotary speed proportionate to the frequency of said voltage and to operational speed of said knitting machine.

12. A knitting machine according to claim 1 including a rotary needle cylinder, and a plurality of knitting stations spaced about said needle cylinder; wherein a thread transporting apparatus is located at each knitting station; wherein said generator means of each thread transporting apparatus is driven from said needle cylinder to generate a polyphase alternating voltage whose frequency is proportionate to the operational speed of said knitting ma chine; and wherein said motor is a polyphase rotary field motor connected to said generator means for receiving said polyphase voltage from the same whereby a rotary field is produced in said motor for driving the same at a rotary speed proportionate to the frequency of said voltage and to the operational speed of said knitting machine so that thread transporting means at each of said knitting stations are driven by their respective motors at varying speeds proportionate to any varied speed of said needle cylinder.

13. A knitting machine according to claim 12 wherein said needle cylinder has a plurality of portions spaced along the circumference thereof; and wherein said generator means of each thread transporting apparatus include impulse producing sensing means stationarily mounted at a point of the periphery of said needle cylinder for sensing said spaced portions and to produce impulses at a frequency proportionate to the operational speed of said needle cylinder, and a polyphase generator receiving said impulses from said impulse producing sensing means for transforming said impulses into a polyphase alternating voltage whose frequency is proportionate to the frequency of said impulses.

14. A knitting machine according to claim 12 wherein said generator means of each transporting apparatus includes a rotary element having a plurality of perforated portions spaced along a circle and being driven from said needle cylinder to rotate with the same about the center of said circle, a source of light in the region of said perforated portions, and photoelectric sensing means for sensing light impluses passing through said perforated portions and producing corresponding control impulses, and a generator receiving said control impulses for transforming the same into a polyphase alternating voltage supplied to said motor.

15. A knitting machine according to claim 12 wherein said thread transporting means include a roller having a plurality circumferential grooves adapted to transport a thread without slippage; and including a movable thread guide having a plurality of positions respectively aligned with said grooves for placing a thread into the same so that a thread moves at different speeds when placed in different grooves while said motor continuously moves at the same speed; and program controlled means connected with said thread guide for moving the same selectively between said positions.

16. A knitting machine according to claim 12 and including a variable transmission driven from said needle cylinder; and wherein said generator means include a rotary polyphase generator driven from said needle cylinder through said transmission means; and including adjusting means for changing the transmissionratio of said transmission; and program controlled selector means connected to said adjusting meansfor adjusting the ratio of said transmission so that the thread is transported at different speed while said needle cylinder moves continuously at the same speed.

17. A knitting machine according to claim 12 including a variable transmission driven from said needle cylinder; adjusting means for adjusting the ratio of said transmission; and program controlled selector means connected to said adjusting means for varying the transmission ratio; and wherein said generator means include a rotary elernent having three concentric circular rows of lightpermeable areas connected with said transmission means and driven from said needle cylinder, a source of light in the regions of said circular rows, three photoelectric sensing means for respectively receiving light impulses passing through said perforations of said rows and connected to each other for producing electric impulses resulting in a polyphase alternating voltage Whose frequency is proportionate to the frequency of said light impulses and to the rotary speed of said needle cylinder and being connetced with said polyphase rotary field motor so that the same drives said thread transporting means at a speed proportionate to any varied speed of the knitting machine.

18. A knitting machine according to claim 12 including a plurality of variable transmissions, each transmission including an adjusting means for adjusting the transmission ratio and a drive member driven from said needle cylinder; wherein said generator means include a plurality of rotary polyphase generators respectively driven by said transmission means for producing polyphase alternating voltages whose frequency is proportionate to the rotary speed of said needle cylinder and also depends on the adjusted ratio of the respective correlated transmission; selector switch means having a plurality of sets of contacts respectively connected to corresponding output terminals of said generators, and a plurality of movable contacts cooperating with said sets of contacts, respectively; and program controlled selector means connected to said movable contacts for moving the same; and wherein a polyphase rotary field motor at each knitting station is connected to a corresponding movable contact so as to receive a polyphase voltage from one of said generators.

19. A knitting machine according to claim 1 comprising a rotary needle cylinder; a plurality of knitting stations spaced about said knitting cylinder; a thread transporting apparatus at each knitting station; a plurality of variable transmission means, each transmission means including an adjusting means for adjusting the transmission ratio and a drive member driven from said needle cylinder; selector switch means having a plurality of sets of first contacts, and a plurality of movable second contacts cooperating with said sets of first contacts, respectively; and program controlled selector means connected to said second contacts for moving the same; and wherein said generator means include a plurality of generators respectively driven by said transmission means for producing impulses at different frequencies proportionate to the rotary speed of said needle cylinder and also depending on the adjusted ratio of the respective transmission; wherein said first contacts are respectively connected to corresponding output terminals of said generators; and wherein said electric motors at each knitting station are respectively connected to said movable second contacts so as to receive impulses from one of said generators, respectively, whereby each of said motors and thread 14 transporting means at each knitting station are driven at rotary speeds proportionate to the rotary speed of the needle cylinder and also depending on the ratio of the selected transmission.

20. A knitting machine according to claim 1 wherein said generator means produces a polyphase alternating voltage whose frequency is proportionate to the operational speed of the knitting machine; and wherein said electric motor is a synchronous motor having three first terminals connected with said generator means for receiving said polyphase alternating voltage, and two second terminals adapted to be connected to a source of dircet current voltage.

21. A knitting machine according to claim 1 comprising a rotary part having a plurality of portions spaced about the circumference thereof; and wherein said generator means include electromagnetic sensing means stationarily mounted at the point of the periphery of said rotary part for sensing said spaced portions and for producing corresponding impulses, an electronic circuit for transforming said pulses into a polyphase alternating voltage; and wherein said electric motor is a polyphase rotary motor having three first terminals connected with said electronic circuit for receiving said polyphase alternating voltage, and two second terminals for receiving an alternating voltage at a predetermined frequency.

References Cited UNITED STATES PATENTS 2,135,756 11/1938 Lawson et a1. 66-132 2,708,841 5/1955 Lumsden 66132 2,773,371 12/1956 Moore 66-154 2,938,365 5/1960 Lassiter 66l32 2,964,252 12/1960 Rosenberg 318-20.l10 X 3,015,806 1/1962 Wang et al. 318-20110 X 3,225,570 12/1965 Mischon 66132 3,232,079 2/1966 Levine et al. 66-154 FOREIGN PATENTS 698,627 10/ 1953 Great Britain.

708,162 4/1954 Great Britain.

829,824 3/ 1960 Great Britain.

MERVIN STEIN, Primary Examiner. W. C. REYNOLDS, Assistant Examiner. 

1. A KNITTING MACHINE, COMPRISING, IN COMBINATION, A THREAD TRANSPORTING APPARATUS INCLUDING GENERATOR MEANS CONTROLLED BY THE KNITTING MACHINE TO GENERATE ELECTRIC IMPULSES AT A FREQUENCY PROPORTIONATE TO THE OPERATIONAL SPEED OF THE KNITTING MACHINE; AN ELECTRIC MOTOR CONNECTED TO SAID GENERATOR MEANS FOR RECEIVING SAID IMPULSES AND HAVING A ROTOR AND DRIVEN BY THE SAME AT A SPEED PROPORTIONATE TO THE FREQUENCY OF SAID IMPULSES AND TO SAID OPERATIONAL SPEED OF THE KNITTING MACHINE; AND THREAD TRANSPORTING MEANS CONNECTED TO AND DRIVEN BY SAID MOTOR WHEREBY SAID THREAD TRANSPORTING MEANS MOVES AT A SPEED VARYING PROPORTIONATE TO ANY VARIED SPEED OF THE KNITTING MACHINE. 